Biggest tire under a stock suspension dart????

why would you want a stock rear suspension with 400+ hp anyway ??? .... i have 255/60r15 but running 002/003 ss springs ... no clearance issues at all ...70 dart 340/4spd

I plan on upgrading to SS springs and poly bushings next summer, have even considered cal-trac. Its a real 340 4 speed car so im not going to mini tub, alter the body or anything like that. I have all the #s matching stuff(engine, radiator, carb, exhaust), because im a resto fag #s guy. lol!!! Just in case I ever decide to put it back to original, or sell.